From fe2a31d790f81bd14a76de3d3b87f4f1362f60cd Mon Sep 17 00:00:00 2001 From: Michal Kubecek Date: Sun, 15 Mar 2020 18:17:43 +0100 Subject: netlink: allow extack cookie also for error messages Commit ba0dc5f6e0ba ("netlink: allow sending extended ACK with cookie on success") introduced a cookie which can be sent to userspace as part of extended ack message in the form of NLMSGERR_ATTR_COOKIE attribute. Currently the cookie is ignored if error code is non-zero but there is no technical reason for such limitation and it can be useful to provide machine parseable information as part of an error message. Include NLMSGERR_ATTR_COOKIE whenever the cookie has been set, regardless of error code. Signed-off-by: Michal Kubecek Signed-off-by: David S. Miller --- net/netlink/af_netlink.c | 43 +++++++++++++++++-------------------------- 1 file changed, 17 insertions(+), 26 deletions(-) (limited to 'net/netlink') diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 5313f1cec170..2f234791b879 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -2392,19 +2392,14 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err, if (nlk_has_extack && extack && extack->_msg) tlvlen += nla_total_size(strlen(extack->_msg) + 1); - if (err) { - if (!(nlk->flags & NETLINK_F_CAP_ACK)) - payload += nlmsg_len(nlh); - else - flags |= NLM_F_CAPPED; - if (nlk_has_extack && extack && extack->bad_attr) - tlvlen += nla_total_size(sizeof(u32)); - } else { + if (err && !(nlk->flags & NETLINK_F_CAP_ACK)) + payload += nlmsg_len(nlh); + else flags |= NLM_F_CAPPED; - - if (nlk_has_extack && extack && extack->cookie_len) - tlvlen += nla_total_size(extack->cookie_len); - } + if (err && nlk_has_extack && extack && extack->bad_attr) + tlvlen += nla_total_size(sizeof(u32)); + if (nlk_has_extack && extack && extack->cookie_len) + tlvlen += nla_total_size(extack->cookie_len); if (tlvlen) flags |= NLM_F_ACK_TLVS; @@ -2427,20 +2422,16 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err, WARN_ON(nla_put_string(skb, NLMSGERR_ATTR_MSG, extack->_msg)); } - if (err) { - if (extack->bad_attr && - !WARN_ON((u8 *)extack->bad_attr < in_skb->data || - (u8 *)extack->bad_attr >= in_skb->data + - in_skb->len)) - WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS, - (u8 *)extack->bad_attr - - (u8 *)nlh)); - } else { - if (extack->cookie_len) - WARN_ON(nla_put(skb, NLMSGERR_ATTR_COOKIE, - extack->cookie_len, - extack->cookie)); - } + if (err && extack->bad_attr && + !WARN_ON((u8 *)extack->bad_attr < in_skb->data || + (u8 *)extack->bad_attr >= in_skb->data + + in_skb->len)) + WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS, + (u8 *)extack->bad_attr - + (u8 *)nlh)); + if (extack->cookie_len) + WARN_ON(nla_put(skb, NLMSGERR_ATTR_COOKIE, + extack->cookie_len, extack->cookie)); } nlmsg_end(skb, rep); -- cgit v1.2.3